Blowpipe



Patented Feb. 22, 1938' BLOWPIPE Wilgot J. Jacobsson, Elizabeth, N. J., assignor, by

mesne assignments, to Union Carbide and Carbon Corporation, a corporation of New York Application November 9, 1934, Serial No. '152,205

l 15 Claims.

This invention relates to the control of `the uid ilow through one of a plurality of passages leading from a common source and has. important application to blqwpipes and particularly to Oxy-gas blowpipes for use in cutting by means of a preheating flame and an oxygen jet wherein the cutting oxygen and that for supporting combustion of the preheating gas are supplied from a common source through divergent branches of a common inlet passage.

In blowpipes of this character the fuel gas for use in preheating the work is supplied from a source through a fuelgas passage, and the oxygen for supporting combustion of the pre'- heating fuel gas and that for cutting are supplied from a common source through branch passages or conduits leading `i'rom a common chamber or main passage. Flow of oxygen from the main passage to supply the cutting jet is through a passage under control of a valve located between the connection of the preheating oxygen passage with the main passage and the tip of the blowpipe. Opening of this valve tends to rob the branch leading to the fuel gas to drop. When the valve is again closed, this pressure is restored and as a consequence the quantitative ow of oxygen from the source to the mixing chamber varies with the opening and closing of this valve. Should the valves controlling the supply of oxygen and, fuel gas to the mixing chamber be originally set for aA neutral mixture with the control valve for the cutting oxygen passage closed, opening of this latter valve will cause the preheating flame to become carbonizing. If the preheating flame is originally adjusted to neutral with the cutting oxygen control valve open, upon closing this valve, the flame will become oxidizing. Neither of these conditions'is desirable in cutting oper- -ations since excess carbon robs the ame of heat', thereby slowing the cutting operation, while a strongly oxidizing ame has relatively poor flashback resistance. -v

Ordinarily, in cutting metals, a high velocity cutting jet is required while in such Work as flame machining, deseaming, and the like a low velocity jet is utilized. Separate special blowpipes have generally been required for these different classes of work, and in some instances a metering plug may be inserted in the head of a single combination blowpipe for throttling down the cutting oxygen passage so as to adapt a high velocity blowpipe for low velocity work. This latter arrangement, whilel better than the (Cl. 15S-27.4)

previous practice, is `unsatisfactcry because an interchange of plugs is impracticable without first cooling the blowpipe head. Furthermore,-

constant regardless of variations in the fluid ow through -another of the branch passages.

A further object of the invention is to provide in a single blowpipe improved means adapting the blowpipe for both high and low velocity cutting jobs and in which interchangeable metering plugs used to this end are not subjected to the heat of the blowpipe ame.

Other objects and novel features of the invention will become apparent from the following description taken with the accompanying drawing illustrating one embodiment of the in vention and in which:

Fig. 1 is a longitudinal section through the handle of a cutting blowpipe showing a construction and arrangements of parts in accordance with this invention;

Fig. 2 is an elevation of the head of the blowpipe on a reduced scale;

Figs. 3 and 4 are cross sectional views respectively' on lines V3--3 and 4--4 of Fig. 1;

Fig. 5 is a fragmentary longitudinal sectional view on line 5 5, Fig. 4, showing the construction arrangement of the metering plug in the cutting oxygen passage of the blowpipe;

Fig. 6 is a detail sectional view on line 6 6 Fig. 1 of the booster-nozzle on an enlarged scale compared with Figs. 1 and 5, showing the construction of the passage therethrough at its discharge end. t

The invention is illustrated in the accompanying drawing as applied to a cutting blowpipe although it is clearly applicable to any analogous device or situation in which it is desired to maintain the flow of uid, through one of a plurality of ,conduits branching from a common source, quantitatively constant regardless of variations in flow that may occur in other of the branch conduits. l The blowpipe, as illustrated, comprisesa head N of usual construction which is connected with a handle H by means 'of a cutting oxygen pipe OL and a pipe C for a preheating mixture. T'he handle H is comprised of a front body or block I6 and a rear body or valve block I I connected by a tubular casing I2,

The front body is bored to provide passages I3 and |4 with the forward ends of whichVpipes Oc and C respectively connect. 'Ihe rear body is also bored to provide a main oxygen passage or chamber O and a fuel gas passage F,- the latter under control of throttle valve I6. Passages O and F are respectively adapted for connection with sources of oxygen and fuel supply through nipples I'I and I8. The main oxygen passage O is connected with passage I3 in the front body by means of a conduit I9 and passage F is connected vwith the passage I4 by a conduit 20 which respectively form continuations of passages O and F. Passage 0 is also connected with the passage I4 by means of a cross passage provided by a conduit 2| which may be provided with a flashback resisting coil 22 located within the casing I2 so as to contact with the walls thereof and thereby provide maximum -bore for accommodation of pipes I9 and 20 and other mechanical accessories, to afford a bracing of the casing walls and afford maximum length of the flashback resisting coil. The passage through conduit 2| is partly formed in the rear body by sultably boring. this body and preferably has a portionV 2|a coaxial with and connected to the forward end of the main oxygen passage O. Flow of .oxygen through conduit 2|.is under control of a throttle valve 24.

Conduit I9 is connected with the forward end of the main oxygen passage 0 by a portion I9a thereof extending radially of the latter passage. Flow of cutting oxygen to the head N through pipe Oc is under control of an operator through valve V located in a valve chamber 25 formed in the front block I0 by counterboring the passageY I3. This valve is normally held closed against a nozzle-like seat 26 by a spring 21 and operates within the bore of a plu'g 29 in which the seat 26 is located. The plug 28 is threaded into the valve chamber 25 and the rear end of this chamber is closed by a plug 29 having a borev3|| therethrough to slidably accommodate the stem 3| of the valve V. The plug 29 is spaced from 29 sufficiently to provide'an inlet chamber 25a constituting a part of valve chamber 25. A leak preventing packing 32 is provided at the rear end lof the plug 29 around stem 3| and is held in place by a gland nut 33. The stem 3|' may be conveniently formed in two parts 3|a and 3|b adjustably connected at 34 for varying the length ,thereof. Stem 3| is extended through the coil .22 and is slidably supported at its rear end in a bearing 3 Ic formed on the rear body or block I I.

The valve V is under control of suitable means operating upon the stem 3|, as a valve-opening lever L of the second class having an arm 35 extending lengthwise of the handle and an arm 36 extending diametrically thereof through a slot 3I in, casing I2 and pivoted at 36a to the rear body. The major portion of arm 36 is therefore enclosed within the casing for purposes of protection thereof and compactness of the apparatus. Lever arm 36 is provided with an opening into which is threaded a set screw 36h for adjustably limiting movement of arm 36. The lever arm 35 is provided at its free end with a slot 38 through which the' shank 39 connecting a latch 4|) to a thumb button 4| extends. The latch 40 is adapted to be extended through a slot 42 in the casing I2 for latchlng the lever,` arm 3| in depressed position and Valve V open. When the outside arm 35 of the L-shaped lever is d6- pressed, the stem 3| will be engaged by a portion of the arm 36 between the pivot 36al and the arm 35, thus pushing the stem 3| forwardly to unseat the valve V.

A mixing chamber M is also provided in the front block., I0 by counterboring passage I4. The mixing chamber M is constructed with a shoulder 43 between which and ring screws 44 threaded thereinto'is held a mixing nozzle 45 having an axial bore 46 of constricted cross section at its discharge end.

The nozzle 45 is provided intermediate its length with an annular groove 4`I constituting a distributing chamber into which the fuel gas conduit 20 discharges. The rear end of the mixing chamber is closed by a plug 48 threaded thereinto and spaced from the ring screws 44 so as to provide an inletchamber 49 into which oxygen conduit 2| discharges. In order to overcome the disadvantages hereinbefore set forth, a baiile member 50 is arranged within the main oxygen passage O to serve as a preheating oxygen booster operating to maintain the iiow of oxygen through conduit 2| quantitatively substantially constant under conditions of an increase in velocity of the gas owing through passage O, when the'cutting oxygen control valve V is either opened or closed. This baffle member is threaded into a counterbore 2 |a of conduit 2 I, is located at the forward end of passage O and is coaxial with this passage and the portion 2| of conduit 2|; the construction being such that the baie member 50 will discharge through portion 2| into conduit 2|. The baille member 50 is provided with an axial bore 5| terminating at its discharge end in a portion 52 internally hexed or otherwise conveniently shaped to accommodate a suitable tool for securing the baiiie in the counterbore or removing vit therefrom. The baiile member 50 extends the major portion of the length of chamber or passage O and is spaced from the wall thereof to `provide an annular chamber 53 which surrounds the nozzle and communicates with conduit I9. 'I'he bale 50 thus serves as a baiile separating the Aow' of oxygen in passage 0 into two parts which are delivered to conduits I9 and 2|, respectively,

In operation, the preheating oxygen normally flows continuously through conduit 2| but, when the cutting oxygen valve V is opened,lthe velocity of the oxygen in passage O increases with an accompan-ying decrease in pressure and would, except for the baiiie member 50, decrease quantita.- tively the flow of preheating oxygen through conduit 2| to the mixing chamber M. By providing the baille 50 and by its peculiar construction and arrangement in passage O as described herein, the increase in velocity of the oxygen due to the sudden inrush of oxygen through passage O, when valve V is opened, causes an increase in the rate of flow into the passage of conduit 2| so that opening of valve V has negligible influence on the quantitative flow of oxygen into the passage of conduit 2|.

In order to adapt the blowpipe to various work conditions, as in changing from high velocity cutting operations todeseaming or low velocity rivet cutting, I have provided a, plurality of metering screw plugs 54 of various lengths to be suitably placed interchangeably in the apparatus to varyingly restrict the cutting oxygen passage. These screws may be placed at any point in the cutting oxygen passage but I preferably place them so as to project from the rear end ofthe rear body Il into the cutting oxygen passage at the juncture between conduit I 9 and the portion I9a thereof. In this position the screw plugs are not likely to become overheated and thereby loosened and, so located, may be removed and replaced at any time without necessity of first allowing the blowpipe to cool.

Variations in the construction and arrangement of parts herein described may obviously -be made within the broad scope of the invention and the invention is not to be restricted 'to blowpipes or to any particular type of blowpipe but is applicable inl whole or in part to various situations where it is desired to maintain the flow of fluid through one of a number of conduits branching from a` common source of supply quantitatively constant regardless of variations in the flow through another of the branches or in the common source.

I claim:

l. A blowpipe havinga fuel gas inlet conduit and an oxygen inlet conduit, said oxygen inlet conduit having its inner end enlarged; branch passages communicating with the enlarged end of said oxygen inlet conduit, one of said branch passages delivering preheating oxygen to be mixed with fuel gas and the otherv branch passage delivering cutting oxygen; said preheating oxygen passage having a removable wall extending into the enlarged end of said oxygen inlet conduit to maintain substantially constant the ow of preheating oxygen regardless of variations in the flow of cutting oxygen.

2. In a blowpipe, a member having fluid passages therethrough; a removable tubular baille member'comprising the inlet end of one of said fluid passages extending into another of said fluid passages and providing communication between said passages; the said baille member having an 'unconstricted passage therethrough for maintaining the ilow of fluid from one of the passages to the other quantitatively constant regardless of changes of lvelocity in the passage from which the gas flows.

3. A member having a fluid inlet passage therein and passages branching from one end thereof;

A to and closing the front and rear ends of said handle; a valve in the front block; a stem entirely within said handle for operating said valve and slidably supported by both of said blocks; means carried b y the rear' block for actuating said stem to operate said valve; a fuel gas inlet conduit and an oxidizing gas inlet conduit, both within the rear block; and conduits extending through said handle and severally communicating with said inlet conduits; one of said communicating conduits within said handle comprising a coiled portion having adjacent coils in close proximity to eachother; said stem and a portion of the other of said communicating conduits being surrounded by said coiled portion.

5. In a blowpipe, the combination of a tubular handle; a fuel gas inlet conduit and an oxidizing gas inlet conduit, both adjacent one end of said handle; conduits extending through said handle and severally communicating with said inlet conduits, one of said conduits within said handle comprising a coil and another of said conduits within said handle extending through said coil; a valve controlling the liowl of gas'through one of the conduits within said handle; and means for operating said valve comprising a stem extending through said coil and projecting beyond the opposite ends of the latter.

6. A blowpipehaving a fuel gas conduit and an oxygen supply conduit, said latter conduit terminating at the exit end thereofin one end of an enlarged chamber; a cutting oxygen conduit communicating with said chamber at a side thereof and a preheating oxygen conduit for deliverlng oxygen to be mixed with the fuel gas, said preheating oxygen conduit extending into said chamber to a point beyond the extrance to said cutting oxygen conduit, and having an inlet portion communicating with said chamber at a point opposite the exit end of the supply conduit.

7. A blowpipe as claimed in claim 6, in which said preheating oxygen conduit is unconstricted and is of smaller diameter than said oxygen supply conduit.

8. A blowpipe as claimed in claim 6, in which the inlet portion of said preheating oxygen conduit extending within said chamber is of smaller diameter than said oxygen supply conduit and is in substantially axial alignment with the exit end thereof. y

9. A blowpipe as claimed in claim 6, in which the outer surface of the inlet end of said extended inlet portion of the preheating oxygen conduit is tapered so as to reduce turbulence in the oxygen flowing to the cutting oxygen conduit. A

10. A blowpipe as claimed in claim 6, in which the said extended inlet portion of the preheating oxygen conduit is removably secured in an end wall of said chamber.

11. A blowpipe comprising, in combination, a tubular handle; a front block secured` to and closing one end of said handle; a rear block secured to and closing the .other end of said handle; a fuel gas conduit and an oxidizing gas conduit, both disposed within said handle; a valve in one of saidblocks controlling the flow of gas through one of said conduits; and means for operating said valve comprising a. valve stem slidingly supported adjacent its ends by said blocks for longitudinal movement within said handle, one of said gas conduits having a coiled portion surrounding a part of the other of said gas conduits between the ends of the latter and also surrounding a part of said valve stem between the ends of the latter.

f l2. A blowpipe comprising, in combination, a tubular handle; a front block secured to and closing one end of said handle; a rear block secured to and closing the other end of said handle; a fuel lgas conduit and an oxidizing gas conduit, both conduits being disposed within said handle;

. a valve carried by one of said blocks and controlling the flow of gas through one of said conduits; means for operating said'valve including a valve stem supported by said blocks for longitudinal movement within said handle, and an L- shaped v,lever having one arm thereof pivoted on the other of said blocks within'said handle and adapted to actuate said valve stem, the other arm of -said lever being disposed outside of and extending along said handle; one of said gas conduits having a coiled portion surrounding a portion of the'other of said gas conduits and a portion of said valve stem.

13. A blowpipe comprising, in combination, a

tubulaihandle; a front block secured to and closing one end of said handle; a rear block secured to and closing the other end of said handle; a fuel gas conduit and two oxidizing gas conduits within said handle; a valve carried by one of said blocks and controlling the iiow of gas through one of said oxidizing gas conduits; and means for operating said valve including a valve stem within said handle and slidingly supported by both of said blocks for movement longitudinally of said handle; the other of said oxidizing gas conduits comprising a coiled portion surrounding a portion of said fuel gas conduit, a portion of said valve stem and a portion of the oxidizing gas conduit controlled by said valve.

14. A blowpipe comprising, in combination, a y

tubular handle; a front block secured to and closing one end of said handle; a rear block secured to and closing the other end of said handle; a

fuel gas conduit Within said handle; two oxidizing gas conduits within said handle; a valve carried by said front block and controlling the flow `of gas through one of said oxidizing gas conduits; and means for operating said valve including an L-shaped lever having arms of unequal length, the shorter leverarm extending into said handle and pivoted adjacent its end on the rear block, and a valve stem within said handle and slidingly supported adjacent its ends by said blocks for movement longitudinally of said handle, a portion of said shorter arm between such pivot and the longer lever arm being adapted to engage an end of said valve stem and actuate the latter to unseat said valve. said longer'lever arm being disposed outside of said handle and extending longitudinally of the latter from adjacent said rear block toward said front block, whereby the free forward end of said longer arm is readily operable by a linger of a hand holding said blowpipe.

15. A blowpipe comprising, in combination, a tubular handle; a front block secured to and closing'one end of said handle; a rear block secured to and closing the other end of said handle; a fuel gas conduit within said handle; two oxidizing gas conduits within said handle; a valve carried by one of said blocks and controlling the flow of gas through one of said oxidizing gas conduits; and means for operating said valve including an L-shaped lever, having arms of unequal length, the shorter lever arm extending into said 'handle and pivoted adjacent its end on the other of said blocks, and a valve stem within said handle and having its ends slidingly supported by said blocks for movement longitudinally of said handle, a portion of said shorter arm between such pivot and the longer lever arm being adapted to engage and actuate said valve stem to unseat said valve, said longer lever arm being disposed outside of said handle and extending lon-v gitudinally thereof, the other ofl said oxidizing gas conduitscomprising a coiled portion within said handle and surrounding a portion of said fuel gas conduit, a portion of said valve stem, and a portion of the oxidizing gas conduit controlled by said valve.

.- WILGOT J. JACOBSSON. 

